For parts that slide while maintaining their sealing performance, such as gaskets each of which is integrated with a syringe plunger and forms a seal between the plunger and the barrel, elastic bodies (e.g. rubber) are used focusing on sealing properties. Such elastic bodies, however, have a slight problem in their sliding properties (see Patent Literature 1). Hence, a sliding property improving agent (e.g. silicone oil) is applied to the sliding surface. It is, however, pointed out that silicone oil can negatively affect recently marketed bio-preparations. On the other hand, a gasket to which a sliding property improving agent is not applied is poor in the sliding properties; therefore, the plunger cannot be pushed smoothly so that it pulsates in administration, thereby causing problems such as inaccuracy in the injection amount and infliction of pain on patients.
In order to simultaneously satisfy such conflicting requirements, that is, the sealing properties and the sliding properties, a technique is proposed in which a self-lubricating PTFE film is applied (see Patent Literature 2). The film, however, is generally expensive and thus increases the production cost of processed products, limiting its application range. Another problem is that since PTFE is vulnerable to radiation, it cannot be sterilized by radiation. Moreover, if the surface of a syringe or catheter is acidic, then the syringe may affect chemical liquids or the catheter may affect the inner body environment such as proteins. Hence, the surface is preferably neutral, bipolar, or hydrophobic.
Furthermore, application to other uses requiring sliding properties in the presence of water may be considered. Specifically, water can be delivered without a loss by reducing the fluid resistance of the inner surface of a pre-filled syringe or the inner surface of a pipe or tube for delivering water, or by making its contact angle with water large or greatly small. Also, drainage of water on wet roads and of snow on snowy roads can be improved by reducing the fluid resistance of the groove surface of tires, or by making its contact angle with water large or greatly small. This results in enhanced hydroplaning resistance and enhanced grip performance, leading to better safety. In addition, less sticking of wastes and dusts can be expected as a result of reducing the sliding resistance of the sidewall surface of tires or walls of buildings, or as a result of making its or their contact angle with water large.
Further advantageous effects can be expected, such as: less pressure loss when water, an aqueous solution or the like is delivered through a diaphragm such as a diaphragm pump or a diaphragm valve; easy sliding of skis or a snowboard by enhancing the sliding properties of the sliding surface thereof; better noticeability of a road sign or a signboard by enhancing the sliding properties thereof to allow snow to slide easily; reduction in water resistance or drag and less sticking of bacteria on the outer peripheries of a ship by reducing the sliding resistance of the outer peripheries or by making their contact angle with water large; and swimsuits with reduced water resistance or drag by improving the sliding properties of the thread surface thereof.